Stringed musical instrument



March 18, 1941. Q A, MAFFE] ETAL 2,235,718

STRINGED MUSICAL INSTRUMENT ATT NEY Mauthl 18, 1.941. D A MAFFE] -rAL 2,235,718

STRINGED MUSICAL INSTRUMENT Filed Sept. 22, 1939 3 slleelLS--Shexl4 2 NIW I' March 18, 1941- D. A. MAFFE! Erm.

STRINGED MUSICAL INSTRUMENT Filed Sept. 22, 1939 3 SheetsS-Sheet 5 Patented Mar. 18, 1941 UNITED STATES PATENT OFFICE STRIN GED MUSICAL INSTRUMENT Application September 22, 1939, Serial No. 296,048

11 Claims.

The present invention relates to stringed musical instruments, especially to instruments of the type of the electric steel guitar, and more particularly to improvements in tuning mechanism for such instruments.

This application for Letters Patent is a continuation-in-part of our copending application Serial vNumber 265,130, -led March 3l, 1939, and relates to certain structural modifications in the improvements therein disclosed.

The principal object of the invention, -is to provide tuning means of a novel type which makes it possi-'ble to obtain a Wide range of pitch variation for each string and to multiply to an extent heretofore Yunknown the number of chord combinations which may be secured by the player of a stringed musical instrument, whether it be a guitar of the modern electronic typo, or any other .of the many stringed musical instruments vwhose musical range has been heretofore limited.

Another object of rthe present invention is to provide in a stringed musical instrument of the above mentioned type, means by which the player may be enabled to accomplish the frequent and rapid changes in tuning vrequired for the rendition of a musical program under modern conditions.

In furtherance .of the aforesaid objects, the invention aims to provide tuning means, auxiliary to the more conventional tuning keys, whereby the tension of each string may be varied selectively at will, with little effort on the part of the player and under his control at all times.

As a feature of the invention, such auxiliary `tuning means comprises a series of rotatable rollers mounted on a shaft upon the body of the instrument, each roller 'being adapted lfor tensioning one of the strings, the rollers being individually connected to suitable operating levers mounted in a compact group conveniently accessible to the hand of the player.

As a further feature of the invention, this group of operating levers is provided with retaining means whereby each of said levers may be held securely in each of a series of adjusted positions to which it may be moved by asimple, easily made, and rapidly completed adjustive movement.

A particular feature of the invention is the provision of balancing means whereby each of the said rollers is urged into a position of normal tension of the Iconnected string, upon return of its corresponding operating .lever to its neutral position.

A further lfeature of the invention is the provision of means whereby all of the said operating levers may be returned to a, neutral posi- 4tion simultaneously by the actuation of a single control device; also the further provision of means whereby the said device for effecting the return of the operating levers to their neutral position, is itself automatically set in an inoperative position leaving the operating levers ready for such further adjustive manipulation as Vmay be desired at any time.

Other objects and advantages of the present invention will in part be pointed out hereinafter and will in part be apparent to those skilled in the art to which the present invention relates.

`With the above and other objects in View the present invention consists of the novel features of construction, combination of elements, and arrangement of parts hereinafter described and illustrated in the accompanying drawings which show the preferred physical embodiment of the invention.

In the accompanying drawings which forni an integral part of this specification,

Fig. l is a plan view of a stringed musical instrument in the construction of which the present invention has been embodied;

Fig. 2 -is a side elevational view thereof Fig. 3 is an yenlarged View in vertical transverse section, taken on the irregular section line 3 3 of Fig. 1;

Fig. 4 is an enlarged fragmentary detail plan showing the operating levers and cooperating members associated therewith;

Fig. 5 is an .enlarged detail view in perspective showing one of the operating levers in operative v connection with its corresponding tensioning roller, together with their respectively associated cross-bar, string and balancing spring;

Fig. 6 is an enlarged fragmentary bottom plan view taken on the line 6 6 of Fig. 2, looking upward.

Referring now to the drawings, which illustrate a stringed musical instrument of the electric guitar type in the construction of which the present invention has been embodied, and wherein like reference characters indicate corresponding'paits throughout the several views, B designates generally the body of the instrument comprising a hollow wooden panel I0 of relatively thick hard wood, which is provided on the upper side thereof with a metal plate I I attached to the panel, as by the studs I2. The body is provided on its upper surface with a suitable fretted fingerboard I3 l,extending longitudinally thereof in the conventional manner, and with the conventlonal tuning keys I4 situated at the head portion of the body.

Strings I5 are tensioned over the body of the instrument and extend longitudinally over the fingerboard I 3 in the conventional manner. The strings l5 are connected at their outer ends to the conventional tuning keys Iii, are guided over suitable guide rolls i6 mounted on a shaft II supported by a pair of brackets I8 at the outer end of the fingerboard, and are secured at their inner ends to rotatable rollers I9 mounted on a shaft 2Q supported by a pair of brackets 2l at the tailward portion of the body. The rotatable rollers I3 constitute an integral part of the auxiliary tuning mechanism to which the present invention relates and will be referred to more particularly hereinafter.

The instrument selected for illustration being an electric steel guitar, there is' shown in Fig. 1 an aperture 22 which is provided in the upper side of the body adjacent the tail end of the instrument, beneath which there is mounted a suitable pick-up device 23 of well known type, which is adapted to transmit the sound vibrations of the strings to an ampliiier and loud-speaker unit associated with the instrument. The pick-up device 23 is preferably provided with suitable volume and tone control means (not shown) which is inserted in the pick-up circuit for modifying the volume and tone of the string vibrations. These controls are adapted to be manually operated by means of control knobs 24 and 25 which are readily accessible to the hand of the player.

In pursuance of the present invention, tuning or string tensioning means of an auxiliary character are provided which are adapted to vary at will the pitch of any of the strings independently of the keys I4 or any other tuning or string tensioning mechanism with which such an instrument may be equipped. A group of such auxiliary tensioning devices is illustrated in the drawings.

This group of auxiliary tensioning devices comprises the rotatable rollers I9, mentioned above, all of which are mounted on a common shaft 20 supported at its ends by the pair of brackets 2l. The rollers I9 are spaced apart by spacing members 26 and the lower portions of the rollers are adapted to project below the surface of the instrument through an opening 2 formed in the upper side of the body. Each of the rollers I9 is provided with a crank-arm 23, which depends into the hollow of the body, the end of which is provided with a series of holes 29 adapted to be entered selectively by a pin 32, which couples therewith in adjusted position the end of a link SI. The link 3| extends to a bell crank lever 32 which is pivotally mounted as at 33 on a supporting bar 34 secured to the body of the instrument, and is coupled in adjusted position with one arm of the bell crank lever 32 in like manner as aforementioned, by a pin 35 which enters into one of the holes 36. Another link 3'! extends from the other arm of the bell crank lever 32 to an operating lever 38, constituting one of a group of such operating levers, and is coupled at both ends in adjusted position, by a pin 39 which enters into one of the holes d in the other arm of the bell crank lever 32, and by a pin 4I which enters into one of the holes 42 of the operating lever 38.

The operating levers 38 are preferably in the form of sector plates mounted upright to rotate upon a horizontal shaft 43, common to all the operating levers, the shaft 43 being Carried by suitable supports within the body of the instrument. The operating levers 38 are separated from each other at their pivot points by spacing sleeves 44 and each leverI is adapted for manual operation independently of the others. The operating levers 38 extend upwardly through an aperture 45 formed in the upper side of the body of the instrument and their upwardly presented arcuate parts are each provided with a terminal handle or button 46 by which the lever may be selected readily and operated easily by one hand of the player. The group of operating levers 38 is mounted in convenient disposition, as shown in Fig. 1, with that portion of the strings I5 0perated upon by the player, and also proximate to the tone and volume control knobs 2li and 25. Preferably the region for manual engagement of the operating levers Will be restricted to the area defined by the edges of a frame il which is secured to the faceplate II, over the aperture 45 in which the group of levers 38 is mounted.

In further pursuance of the present invention, and to serve the purpose of retaining means for holding the operating levers 38 in any selected position of several such possible positions, there is provided, in the instance illustrated, a series of index bars 48, one for each lever, each of said index bars 48 being arranged in parallelism with the face of one of the levers and in spaced relation thereto, and secured at the ends thereof to the upper surface of the body of the instrument as by the studs 49. The index bars 43 are preierably arcuate in form to conform to the curvature of the upper portions of the operating levers 38, and the inner edge of each index bar i8 is provided with a plurality of notches or recesses 50 to receive its corresponding lever 38 in say ive positions of tensional adjustment of one ofthe strings. This structure is illustrated in detail in Fig. 4, which iigure also shows means for aiding the operating levers 38 to be engaged retentively in their several adjustive positions, while making it possible also to move them freely to different positions of adjustment at will.

For this purpose, the upper portion of the face of each operating lever 3B which is adjacent the recesses 52 of its associated index bar 43, is provided with a resilient iinger or prong 5I having a laterally extending bolt 52 which normally bears against the edge of the index bar 48 and is adapted to be retentively engaged within any one of the recesses 58. The recesses 52 are preferably tapered inwardly and the bolts 52 are correspondingly tapered to permit of ready locking engagement between the two parts when the operating levers 38 are moved by the player to required adjustive positions, and also to permit the bolts 52 to be easily and readily released from their recesses 5i! when'the operating levers are moved by the player to other and diiferent adjustive positions.

It will be understood from the foregoing description that the operative connection between each operating lever 38 and its corresponding string tensioning roller iS is such that upon operation `of the lever 38, its pivotal movement will be transmitted by means of the connecting links 3'! and 3| and the intermediate bell crank lever 32 to the crank arm 28 of the string tensioning roller 19, and the roller I9 will be caused to rotate in a corresponding manner, whereby the tension of the connected string I5 will be correspondingly varied. The levers 38 andv their corresponding tensioning rollers I9 are preferably connected in such operative relation, that when the levers 38 `have .their handles .46 disposed in a central position with reference to opposite sides of the aperture v45, then the tensioning rollers I9 are in position of normal tension of the connected strings. Accordingly, mjovement of the levers 38 to one side of their central or neutral positions will cause an increase in the tension of the strings I5 and movement to the opposite side Will cause the tension of the strings I5 to be decreased.

In further pursuance of the present invention, each lever 38 is provided with a body opening 53, having downwardly rounded walls `forming a groove 54 adjacent to the fulcrum shaft 43, and adapted to receive therein a cross-bar 55 carried by the arms of a pivoted U-shaped lever 55. The U-shaped lever 56 is adapted to embrace all of the levers 38 as a group, its ends being pivoted within the body of the instrument as at 51. The portion 58, which spans the arms of the U-shaped lever 56, projects upwardly through the aperture inthe upper side of the body of the instrument, and provides a hand rest for manual operation of the lever.

The cross-bar carried by the U-sha'ped lever 58 transxes all the operating levers 38, extending through their body apertures 53 from side to side of the group, and is designed to enter the grooves 54 of the operating levers when the player presses down with his hand on the hand rest 58 of the U-shaped lever 55, to permit the operating levers 38 to be thrown simultaneously into neutral position, so that all of the string tensioning rollers i9 may, .at will, be restored to a position of normal tension of the connected strings. Thus, a single volitional act by the player suices to release the operating levers as a group, from the last adjusted positions to which they may have been moved by the player, and to restore them to their neutral positions.

The underside of the hand rest 58 is preferably provided with soft rubber pads or cushions 59 to ease and absorb the shock that may be produced from the operation of the lever 55.

A spring 60 is provided, and is adapted to engage one of the arms of the U-shaped lever 55 and hold it in inoperative position, wherein the cross-bar 55 is out of engagement position with the grooves 54 of the operating levers 38, as shown in Figs. 3 and 5, so as to permit movement of the operating levers relative to the crossbar 55 to the desired adjusted positions. When the pressure of the players hand is removed from the hand rest 58, after the lever 56 has been operated to restore the operating levers 38 to their neutral positions, ythe spring B9 acts to return the lever 56 to its original inoperative position, and the operating levers are thus free and ready to be again operated as desired,

In further pursuance of the present invention, the tailward portion of each string .I5 is attached `to its corresponding tensioning roller I9 by coiling it over the roller inthe manner indicated in Fig. 5, the end of the string being secured to the roller by a pin (not shown) which is adapted to be engaged within a suitable hole in the periphery of the roller. The tensioning rollers I9 are preferably provided with annular grooves 6I Within which the strings I5 are retained against possible displacement. Rearwardly of the tensioning rollers I9 there is provided a series of tension Ysprings 62, in substantial alignment with the strings I5, and each .of the springs 62 is connected at one end'to .one of the tensioning rollers I9 by Aa flexible jmetal strip -53 which .is coiled over the roller in a direction ,counter to that of its associated string I5, the end .of .the strip 63 being secured by a pin (not known) which is adapted to be engaged within a suitable hole in the periphery of the roller. The .other end ,of each tension spring 52 is connected to a wrench faced stud 64 by a wire 65 which is wound thereupon and secured thereto in a suitable manner. The studs 64 are mounted threadedly on the body of the instrument and are rotatable by means of a hand key or like instrument for the purpose of adjusting the tension of the springs 62.

In preparing the instrument for practice of the invention, it is required that the instrument be rst tuned to basic or normal tensional adjustment of the strings. This may be readily accomplished by manipulation of the conventional tuning keys I4, whereby each string is individually tensioned to its normal pitch. It will be underj index bars 48. The studs E4 are then rotated with i a suitable key wrench or the like, to adjust the tension springs v62 so that each of the springs exerts a tension upon its associated tensioning roller I9 equal to the tension exerted by the string I5 at its normal pitch adjustment. In view of the A -fact that the strings I5 land the connecting strips 6.3 of the springs 62 are wound upon the tensioning rollers in opposite directions, and the opposite tensions upon each tensioning roller are equally balanced, as rheretofore pointed out, it will be apparent that each tensioning roller is thus normally maintained against rotation in either direction.

It will :be evident, that when the tensioning roller I9 is rotated, as upon movement of the operating lever 38 to an adjusted position, the opposite tensions of the string I5 and the spring 92 thereby become unbalanced. For example, when the lever 38 is operated for rotating the tensioning roller i9 so as to increase the tension of the connected string above its normal tensional adjustment, then the tension of the spring 62 will be relaxed below its normal tensional adjustment; likewise, when the lever Y38 is moved to rotate the tensioning roller so as to decrease the tension of the connected string below its normal tensional adjustment, then the tension of the spring 62 wil be increased above normal tensional adjustment. When, therefore, the lever 38 is released from a retained position of above normal tensional adjustment, and returned to neutral position, then the increased tension of the string I5 will tend to counter rotate the tensioning roller I9 toward its normal tensioning position. In a similar manner, when the lever 38 is release from a retained position of below normal tensional adjustment, and returned to neutral position, then .the increased tension of the spring E2 will tend to counter rotate the tensioning roller I S toward its normal tensioning position. The foregoing balancing arrangement is therefore designed to urge the tensioning rollers I9 at all times toward position for restoring the strings to i a state of normal tensional adjustment.

In the practice of the invention, each oi the operating levers is adapted for movement by the hand of the player into ve distinct adjusted positions, namely neutral position, and two positions .oneachgside .of the neutral position. These positions of vadjustment are preferably arranged to provide for adjusting the tension of the strings in equal steps, so that the pitch of each string may be varied a half-tone upon movement of the corresponding lever from one adjusted position to an adjacent position. Each of the strings may thus be stretched two half-tones above normal pitch and contracted two half-tones below normal pitch.

From the foregoing disclosure, it Will be clear that the novel tuning or tensioning mechanism constituted by the instrurnentalities illustrated and above described, provides for a wide range of pitch variation of each string, and for rapid execution with but little eiort on the part of the player and under his control at all times.

That the present invention has achieved the stated object of increasing to an iniinitely greater extent, the number of chord combinations which may be obtained by the player of a stringed instrument will be realized When it is considered that in the instrument herein illustrated by Way of example it is possible to secure five half-tone pitch variations for each of seven strings, the various pitches of the strings being capable of grouping in many diierent combinations. One can readily appreciate the almost incalculable number of chord combinations possible in a stringed musical instrument having an indenitely greater number of pitch variations for each of a much larger number of strings limited only by considerations of space and convenience in structural arrangement, the invention being of universal application and amplication.

While we have illustrated and described herein the noW preferred embodiment of our invention, it is however to be clearly understood that we do not desire to be limited to the speciiic details of construction herein shown and disclosed, for obvious changes in construction are contemplated, which will fall Within the spirit and scope of our invention as defined in the 'appended claims.

Having thus described and illustrated our invention, what we claim as new and desire to secure by Letters Patent is:

l. In a stringed musical instrument having a plurality of strings tensioned thereon, means for selectively varying the pitch of each of said strings, said means comprising a plurality of string tensioning rollers mounted on a common axis and independently rotatable thereon, each of said rollers having one end of one of the strings attached thereto and Windable thereon to and from -a normal tensioning position, a plurality of manually operable levers pivotally mounted upon a common axis and each independently movable to either side of a normal position about said common axis, and means operatively connecting the levers to the string tensioning rollers whereby rotation of -any one of said levers will cause a corresponding rotation of its connected string tensioning rollers in either direction from its normal tensioning position upon corresponding operation of its connected lever to thereby vary the pitch of the string attached to the said tensioning roller.

2. In a stringed musical instrument having a plurality of strings tensioned thereon, means for selectively varying the pitch of each of said strings, said means comprising a plurality of string tensioning rollers mounted on a common axis and independently rotatable thereon, each of said rollers having one end of one of the strings attached thereto and windable thereon to and from a normal tensioning position, alpluraltions.`

-ity of manually operable levers pivotally mounted upon a Acommon axis and each independently movable to either side of a normal position about said common axis, means openatively connecting the levers to the string tensioning rollers whereby v rotation of any one of saidlevers will cause a corresponding rotation of its connected string tensioning roller in either direction from its normal tensioning position upon corresponding operation of its connected lever to thereby vary theV pitch of the string attached to the said tensioning roller, and a locking device associated With each lever and engaging a iixed part of the instrument to retain said lever and its connected string tensioning roller in a selected string ten-4 y sioning position of a plurality of possible adjustive positions.

3. In a stringed musical instrument having a plurality of strings tensioned thereon, means for selectively varying the pitch of each of said strings, said means comprising a plurality of string tensioning rollers mounted on a common axis and independently rotatable thereon, each of said rollers having one end of one of the strings attached thereto and windable thereon to and f from a normal Itensioning position, a plurality of manually operable levers pivotally mounted upon a common axis and each independently movable to either side of a norm-a1 position about said common axis, means operatively connecting thef levers to the string tensioning rollers whereby rotation of any one of said levers will cause a corresponding rotation of its connected string tensioning roller in either direction from its normal tensioning position upon corresponding op- 3 eration of Aits connected lever to thereby vary the pitch of the string attached to the said tensioning roller, a locking device associated with eachstrings, said means comprising a plurality of string tensioning rollers mounted on a common axis and independently rotatable thereon, each of said rollers having one end of one of the strings attached thereto and Windable thereon to and from a normal tensioning position, a plurality of manually openable levers pivotally mounted upon a common axis and each independently movable to either side of a normal position about said common axis, means operatively connecting the levers to the string tensioning rollers whereby rotation of any one of said levers will cause a corresponding rotation of its connected string tensioning roller in either direction from its normal tensioning position upon corresponding operation of its connected lever to thereby vary the pitch of the string attached to the said tensioning roller, a locking device carried by each lever and including resilient means for normally urging said locking device to a locking position, and a fixed index member adjacent each lever and eng-ageable by said locking device, said index member having a series of spaced recesses therein to selectively receive said locking device to retain said lever in any one of several adjustive posimusical instrument having a 75 plurality of strings tensioned thereon, means for selectively varying the pitch of each of said strings, said means comprising a plurality of string tensioning rollers mounted on a common axis and independently rotatable thereon, each of said rollers having one end of one of the strings attached thereto and Windable thereon to and from a normal tensioning position, a plurality of manually operable levers pivotally mounted upon a common axis and each independently movable to either side of a normal position about said common axis, means operatively connecting the levers to the string tensioning rollers whereby rotation of any one of said levers will cause a corresponding rotation of its connected string tensioning roller in either direction from its normal tensioning position upon corresponding operation of its connected lever to thereby vary the pitch of the string attached to the said tensioning roller, a resilient prong carried by said lever, a iixed index member adjacent each lever and prong, said index member having a series of spaced recesses therein selectively engageable by said prong whereby the lever may be retained in any one of several adjustive positions, and means engaging said levers for releasing said prongs from engagement with selected recesses and returning said levers and their connected string tensioning rollers to their normal string tensioning positions.

6. In a stringed musical instrument having a plurality of strings tensioned thereon, means for selectively varying the pitch of each of said strings, said means comprising a series of string tensioning rollers mounted on a common axis and independently rotatable thereon, each of said rollers having an end of one of the strings attached thereto and Windable thereon to and from a normal tensioning position, a corresponding series of manually operable levers pivotally mounted on a common axis and each movable independently of the others to either side of a normal position about said common axis, means operatively connecting the levers to the string tensioning rollers whereby rotation of a selected lever will cause a corresponding rotation of the roller to which it is operatively connected, a resilient locking device associated with each of said levers and engaging a iixed part of the instrument to retain said lever and its connected string tensioning roller in one of a plurality of possible adjustive positions, and a manually operable lever engageable with all of the iirst-mentioned levers as a group to simultaneously release said resilient locking devices and to return said levers and their connected string tensioning rollers to their normal string tensioning positions.

7. In a stringed musical instrument having a plurality of strings tensioned thereon, means for selectively varying the pitch of the several strings, said means comprising a series of string tensioning rollers mounted upon a common axis and each having one end of one of the strings attached thereto and Windable thereon to and from a normal tensioning position, a corresponding series oi manually operable sector-levers pivotally mounted on a common axis and movable independently of each other to either side of a neutral position, means operatively connecting each of said sector-levers to its corresponding tensioning roller to rotate said roller upon rotation of its corresponding lever, a resilient locking device associated With each of said levers and engaging a fixed part of the instrument to retain said lever resiliently in one of a'plurality of possible adjustive positions, said sector-levers having alined, similarly disposed body apertures formed therein, a movable cross-bar translxing said apertures, which bar, when in one position within the body apertures, permits independent movement of said sector-levers to permit locking thereof by said resilient locking device and, when in another position, engages a Wall defining the said body apertures, and a lever connected to said cross-bar and operable manually to simultaneously release said sector-levers from their locked adjusted positions and to return them to their neutral positions.

8. In a stringed musical instrument having a plurality of strings tensioned thereon, means for selectively varying the pitch of the severa-l strings, said means comprising a series of string tensioning rollers mounted on a common axis and each having one end of one of the strings attached thereto and Wind-able thereon to and from a normal tensioning position, a corresponding series of manually operable sector-levers pivotally mounted on a common axis and movable independently of each other away from a neutral position, means operatively connecting each of said sector-levers to its corresponding tensioning roller to rotate said roller upon rotation of its corresponding lever, a resilient locking device as'- sociated with each of said levers and engaging a fixed part of the instrument to retain said lever resiliently in one of a plurality of possible adjustive positions, said sector-levers having alined similarly disposed body apertures formed therein, a movable cross-bar transxing said apertures, which bar, when in one position Within the body apertures, permits independent movement of said sector-levers to permit locking thereof by said locking device and, When in another position, engages a Wall dening the said body apertures, a pivotally mounted lever connected to said crossbar and operable manually to bring said crossbar into locking relation simultaneously with all of the sector-levers, and spring means normally urging said last-mentioned lever and its associated cross-bar into a position to permit independent adjustment and locking of the sectorlevers.

9. In a stringed musical instrument having a plurality of strings tensioned thereon, means for selectively varying the pitch of each of said Y strings, said means comprising a plurality of string tensioning rollers mounted on a common axis and independently rotatable thereon, each of said rollers having one end of one of the strings attached thereto and Windable thereon in a given direction, a plurality of manually operable levers pivotally mounted upon a common axis and each independently movable to either side of a normal position about said common axis, means operatively connecting the levers to the string tensioning rollers whereby rotation of any one of said levers Will cause a corresponding rotation of its connected string tensioning roller in either direction from its normal tensioning position upon corresponding operation of its connected lever to thereby Vary the pitch of the string attached to the said tensioning roller, and a plurality of tension springs aligned With the plurality of strings on the instrument, each of said springs having a exible connecting member Windable upon one of said string tensioning rollers in a direction counter to that of the string, lsaid tension springs urging the tensioning rollers into their normal tensioning positions when the levers are moved to their normal position.

10. In a stringed musical instrument having a plurality of strings tensioned thereon, means for selectively varying the pitch of each of said strings, said means comprising a plurality of string tensioning rollers mounted on a common axis and independently rotatable thereon, each of said rollers having one end of one of the strings attached thereto and windable thereon in a given direction, a plurality of manually operable levers pivotally mounted upon a common axis and each independently movable to either side of a normal position about said common axis, means operatively connecting the levers to the string tensioning rollers whereby rotation of any one of F said levers will cause a corresponding rotation of its connected string tensioning roller in either direction from its normal tensioning position upon corresponding operation of its connected lever to thereby vary the pitch of the string attached to the said tensioning roller, 4and a plurality of tension springs aligned With the plurality of strings on the instrument, each of said springs having one end thereof connected to a xed support positioned rearwardly of the plurality of string tensioning rollers and each having at its other end a flexible connecting member Windable upon one of the tensioning rollers in a direction counter to that of the string connected to said roller, said tension spring counterbalancing the tension of the string on said string tensioning roller.

11. In a stringed musical instrument having a plurality of strings tensioned thereon, means for varying the pitch of each of the strings, said means comprising a plurality of string tensioning rollers mounted on a common axis and lndependently rotatable thereon, each of said rollers having the tailvvard end of one of said strings attached thereto and windable thereon to and from a normal tensioning position, a plurality of manually operable levers pivotally mounted upon a common axis and each independently movable to either side of a normal position about a common axis, means operatively connecting the levers to the string tensioning rollers whereby rotation of any one of said levers will cause a corresponding rotation of its connected string tensioning roller in either direction from it-s normal tensioning position upon corresponding operation of its connected lever to thereby vary the pitch of the string attached to the said tensioning roller, a plurality of tension springs aligned with the plurality of strings and positioned rearwardly of the plurality of string tensioning rollers, and a plurality of fixed anchorage posts positioned rearwardly of the string tensioning rollers and springs, each of said springs having one end thereof connected to one of the fixed anchorage posts and having at its other end a ilexible connecting member windable upon one of the string tensioning rollers in a direction counter to that of the connected string on said roller, each tension spring urging its connected tensioning roller into normal tensioning position.

DOMINICK A. MAFFEI. CLYDE C. DOERR. 

